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1.
Soc Neurosci ; 16(4): 448-465, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34133907

RESUMO

The extrastriate body area (EBA) in the lateral occipito-temporal cortex has an important role in reciprocal interaction, as it detects congruence between self and other's hand actions. However, it is unclear whether the EBA can detect congruence regardless of the type of action. In the present study, we examined the neural substrate underlying congruence detection of three types of actions: hand gestures, vocalizations, and facial expressions. A univariate analysis revealed a congruency effect, especially for imitating action, for all three types of actions in the EBA. A multi-voxel pattern analysis classifier in the EBA was able to distinguish between initiating interaction from responding to interaction in all experiments. Correspondingly, the congruency effect in the EBA revealed by univariate analysis was stronger for responding to than for initiating interaction. These findings suggest that the EBA might contribute to detect congruence regardless of the body part used (i.e. face or hand) and the type of action (i.e. gestural or vocal). Moreover, initiating and responding to interaction might be processed differently within the EBA. This study highlights the role of the EBA in comparing between self and other's actions beyond hand actions.Running head: Function of EBA in reciprocal imitation.


Assuntos
Gestos , Imageamento por Ressonância Magnética , Mapeamento Encefálico , Expressão Facial , Humanos , Comportamento Imitativo
2.
Nutrients ; 12(6)2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32498248

RESUMO

Our double-blind, placebo-controlled study evaluated effects of ubiquinol, the reduced form of coenzyme Q10, on mild fatigue in healthy individuals experiencing fatigue in daily life that had continued for more than 1 and less than 6 months. The participants received 100-mg/day (Ubq100; age 44.0 ± 9.8 years; 14 females and 6 males) or 150-mg/day ubiquinol (Ubq150; age 40.4 ± 11.8 years; 14 females and 8 males) or placebo (Plc; age 41.3 ± 13.4 years; 13 females and 7 males) daily for 12 weeks. Measurements of subjective and objective fatigue were conducted by using questionnaires-based fatigue scales/visual analogue scales and autonomic nerve function/biological oxidation index, respectively, prior to the first dosing and every 4 weeks thereafter. Serum ubiquinol level increased three- to four-fold after 4 weeks and remained significantly higher than that after Plc administration throughout the intake period. Although a higher blood level of ubiquinol was observed with Ubq150 than with Ubq100, the difference was not statistically significant. In both Ubq100 and Ubq150 groups, subjective levels of fatigue sensation and sleepiness after cognitive tasks, which consisted of the modified Advanced Trail Making Test, the modified Stroop Color-Word Test, and the Digit Symbol Substitution Test, improved significantly compared with those in the placebo group, suggesting an anti-fatigue effect. The Ubq150 group demonstrated significant improvement compared with the Plc group regarding subjective level of relaxation after task, sleepiness before and after task, motivation for task, and serum level of oxidative stress. Correlation analysis between blood level of ubiquinol and each evaluated effect suggested a positive relationship with relaxation after task, motivation for cognitive task, and parasympathetic activity. The results of the study suggest that ubiquinol intake relieves mild fatigue in healthy individuals.


Assuntos
Suplementos Nutricionais , Fadiga/tratamento farmacológico , Voluntários Saudáveis , Fenômenos Fisiológicos da Nutrição/fisiologia , Ubiquinona/análogos & derivados , Adulto , Método Duplo-Cego , Fadiga/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Estresse Oxidativo/efeitos dos fármacos , Relaxamento , Inquéritos e Questionários , Ubiquinona/administração & dosagem , Ubiquinona/sangue
3.
Sci Rep ; 9(1): 8797, 2019 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-31217505

RESUMO

Previous studies have revealed that patients with chronic fatigue syndrome and affective disorders (such as depression and anxiety disorders) exhibit a vigilant attentional bias toward negative emotional stimuli. However, it remains unclear whether the change in an attentional bias for negative emotional stimuli can be induced by mental fatigue in healthy individuals. To address this question, we examined healthy participants' (n = 27) performance in a visual probe task and emotional Stroop task before and after the mental-fatigue-inducing task. We demonstrated that acute mental fatigue induced by the long-lasting working memory task led to the alteration of cognitive processing of negative emotional information in the healthy volunteers.


Assuntos
Viés de Atenção/fisiologia , Emoções/fisiologia , Fadiga Mental/fisiopatologia , Estimulação Luminosa , Adulto , Afeto , Feminino , Humanos , Masculino , Teste de Stroop , Análise e Desempenho de Tarefas
4.
Soc Cogn Affect Neurosci ; 14(10): 1131-1145, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31919530

RESUMO

Understanding others as intentional agents is critical in social interactions. We perceive others' intentions through identification, a categorical judgment that others should work like oneself. The most primitive form of understanding others' intentions is joint attention (JA). During JA, an initiator selects a shared object through gaze (initiative joint attention, IJA), and the responder follows the direction of the initiator's gaze (reactive joint attention, RJA). Therefore, both participants share the intention of object selection. However, the neural underpinning of shared intention through JA remains unknown. In this study, we hypothesized that JA is represented by inter-individual neural synchronization of the intention-related activity. Additionally, JA requires eye contact that activates the limbic mirror system; therefore, we hypothesized that this system is involved in shared attention through JA. To test these hypotheses, participants underwent hyperscanning fMRI while performing JA tasks. We found that IJA-related activation of the right anterior insular cortex of participants was positively correlated with RJA-related activation of homologous regions in their partners. This area was activated by volitional selection of the target during IJA. Therefore, identification with others by JA is likely accomplished by the shared intentionality of target selection represented by inter-individual synchronization of the right anterior insular cortex.


Assuntos
Atenção/fisiologia , Córtex Cerebral/fisiologia , Relações Interpessoais , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
5.
Cortex ; 108: 234-251, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30261368

RESUMO

Detecting relationships between our own actions and the subsequent actions of others is critical for our social behavior. Self-actions differ from those of others in terms of action kinematics, body identity, and feedback timing. Thus, the detection of social contingency between self-actions and those of others requires comparison and integration of these three dimensions. Neuroimaging studies have highlighted the role of the frontotemporal network in action representation, but the role of each node and their relationships are still controversial. Here, we conducted a functional MRI experiment to test the hypothesis that the lateral prefrontal cortex and lateral occipito-temporal cortex are critical for the integration processes for social contingency. Twenty-four adults performed right finger gestures and then observed them as feedback. We manipulated three parameters of visual feedback: action kinematics (same or different gestures), body identity (self or other), and feedback timing (simultaneous or delayed). Three-way interactions of these factors were observed in the left inferior and middle frontal gyrus (IFG/MFG). These areas were active when self-actions were directly fed back in real-time (i.e., the condition causing a sense of agency), and when participants observed gestures performed by others after a short delay (i.e., the condition causing social contingency). In contrast, the left extrastriate body area (EBA) was sensitive to the concordance of action kinematics regardless of body identity or feedback timing. Body identity × feedback timing interactions were observed in regions including the superior parietal lobule (SPL). An effective connectivity analysis supported the model wherein experimental parameters modulated connections from the occipital cortex to the IFG/MFG via the EBA and SPL. These results suggest that both social contingency and the sense of agency are achieved by hierarchical processing that begins with simple concordance coding in the left EBA, leading to the complex coding of social relevance in the left IFG/MFG.


Assuntos
Comportamento Imitativo/fisiologia , Lobo Occipital/fisiologia , Córtex Pré-Frontal/fisiologia , Lobo Temporal/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Mapeamento Encefálico , Sinais (Psicologia) , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Lobo Occipital/diagnóstico por imagem , Estimulação Luminosa , Córtex Pré-Frontal/diagnóstico por imagem , Lobo Temporal/diagnóstico por imagem , Adulto Jovem
6.
Neuroscience ; 352: 190-203, 2017 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-28396007

RESUMO

The intrinsic value of an action refers to the inherent sense that experiencing a behavior is enjoyable even if it has no explicit outcome. Previous research has suggested that a common valuation mechanism within the reward network may be responsible for processing the intrinsic value of achieving both the outcome and external rewards. However, how the intrinsic value of action is neurally represented remains unknown. We hypothesized that the intrinsic value of action is determined by an action-outcome contingency indicating the behavior is controllable and that the outcome of the action can be evaluated by this feedback. Consequently, the reward network should be activated, reflecting the generation of the intrinsic value of action. To test this hypothesis, we conducted a functional magnetic resonance imaging (fMRI) investigation of a stopwatch game in which the action-outcome contingency was manipulated. This experiment involved 36 healthy volunteers and four versions of a stopwatch game that manipulated controllability (the feeling that participants were controlling the stopwatch themselves) and outcome (a signal allowing participants to see the result of their action). A free-choice experiment was administered after the fMRI to explore preference levels for each game. The results showed that the stopwatch game with the action-outcome contingency evoked a greater degree of enjoyment because the participants chose this condition over those that lacked such a contingency. The ventral striatum and midbrain were activated only when action-outcome contingency was present. Thus, the intrinsic value of action was represented by an increase in ventral striatal and midbrain activation.


Assuntos
Mapeamento Encefálico , Comportamento de Escolha/fisiologia , Mesencéfalo/fisiologia , Motivação/fisiologia , Recompensa , Estriado Ventral/fisiologia , Adolescente , Adulto , Feminino , Voluntários Saudáveis , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Mesencéfalo/diagnóstico por imagem , Oxigênio/sangue , Estriado Ventral/diagnóstico por imagem , Percepção Visual , Adulto Jovem
7.
Med Gas Res ; 7(4): 247-255, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29497485

RESUMO

Health and a vibrant life are sought by everyone. To improve quality of life (QOL), maintain a healthy state, and prevent various diseases, evaluations of the effects of potentially QOL-increasing factors are important. Chronic oxidative stress and inflammation cause deteriorations in central nervous system function, leading to low QOL. In healthy individuals, aging, job stress, and cognitive load over several hours also induce increases in oxidative stress, suggesting that preventing the accumulation of oxidative stress caused by daily stress and daily work contributes to maintaining QOL and ameliorating the effects of aging. Hydrogen has anti-oxidant activity and can prevent inflammation, and may thus contribute to improve QOL. The present study aimed to investigate the effects of drinking hydrogen-rich water (HRW) on the QOL of adult volunteers using psychophysiological tests, including questionnaires and tests of autonomic nerve function and cognitive function. In this double-blinded, placebo-controlled study with a two-way crossover design, 26 volunteers (13 females, 13 males; mean age, 34.4 ± 9.9 years) were randomized to either a group administered oral HRW (600 mL/d) or placebo water (PLW, 600 mL/d) for 4 weeks. Change ratios (post-treatment/pre-treatment) for K6 score and sympathetic nerve activity during the resting state were significantly lower after HRW administration than after PLW administration. These results suggest that HRW may reinforce QOL through effects that increase central nervous system functions involving mood, anxiety, and autonomic nerve function.

8.
Neuroimage Clin ; 12: 600-606, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27709065

RESUMO

Motivational signals influence a wide variety of cognitive processes and components of behavioral performance. Cognitive dysfunction in patients with childhood chronic fatigue syndrome (CCFS) may be closely associated with a low motivation to learn induced by impaired neural reward processing. However, the extent to which reward processing is impaired in CCFS patients is unclear. The aim of the present functional magnetic resonance imaging (fMRI) study was to determine whether brain activity in regions related to reward sensitivity is impaired in CCFS patients. fMRI data were collected from 13 CCFS patients (mean age, 13.6 ± 1.0 years) and 13 healthy children and adolescents (HCA) (mean age, 13.7 ± 1.3 years) performing a monetary reward task. Neural activity in high- and low-monetary-reward conditions was compared between CCFS and HCA groups. Severity of fatigue and the reward obtained from learning in daily life were evaluated by questionnaires. Activity of the putamen was lower in the CCFS group than in the HCA group in the low-reward condition, but not in the high-reward condition. Activity of the putamen in the low-reward condition in CCFS patients was negatively and positively correlated with severity of fatigue and the reward from learning in daily life, respectively. We previously revealed that motivation to learn was correlated with striatal activity, particularly the neural activity in the putamen. This suggests that in CCFS patients low putamen activity, associated with altered dopaminergic function, decreases reward sensitivity and lowers motivation to learn.


Assuntos
Síndrome de Fadiga Crônica/fisiopatologia , Síndrome de Fadiga Crônica/psicologia , Putamen/fisiopatologia , Recompensa , Adolescente , Mapeamento Encefálico , Criança , Feminino , Humanos , Aprendizagem/fisiologia , Imageamento por Ressonância Magnética , Masculino , Motivação/fisiologia , Tempo de Reação
9.
Neuropsychologia ; 87: 74-84, 2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-27157883

RESUMO

A hearer's perception of an utterance as sarcastic depends on integration of the heard statement, the discourse context, and the prosody of the utterance, as well as evaluation of the incongruity among these aspects. The effect of prosody in sarcasm comprehension is evident in everyday conversation, but little is known about its underlying mechanism or neural substrates. To elucidate the neural underpinnings of sarcasm comprehension in the auditory modality, we conducted a functional MRI experiment with 21 adult participants. The participants were provided with a short vignette in which a child had done either a good or bad deed, about which a parent made a positive comment. The participants were required to judge the degree of the sarcasm in the parent's positive comment (praise), which was accompanied by either positive or negative affective prosody. The behavioral data revealed that an incongruent combination of utterance and the context (i.e., the parent's positive comment on a bad deed by the child) induced perception of sarcasm. There was a significant interaction between context and prosody: sarcasm perception was enhanced when positive prosody was used in the context of a bad deed or, vice versa, when negative prosody was used in the context of a good deed. The corresponding interaction effect was observed in the rostro-ventral portion of the left inferior frontal gyrus corresponding to Brodmann's Area (BA) 47. Negative prosody incongruent with a positive utterance (praise) activated the bilateral insula extending to the right inferior frontal gyrus, anterior cingulate cortex, and brainstem. Our findings provide evidence that the left inferior frontal gyrus, particularly BA 47, is involved in integration of discourse context and utterance with affective prosody in the comprehension of sarcasm.


Assuntos
Encéfalo/fisiologia , Compreensão/fisiologia , Emoções/fisiologia , Idioma , Adulto , Mapeamento Encefálico , Feminino , Humanos , Julgamento/fisiologia , Testes de Linguagem , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Reconhecimento Visual de Modelos/fisiologia , Reconhecimento Psicológico/fisiologia , Percepção da Fala/fisiologia , Senso de Humor e Humor como Assunto , Adulto Jovem
10.
Neuroimage ; 125: 401-412, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26514295

RESUMO

During a dyadic social interaction, two individuals can share visual attention through gaze, directed to each other (mutual gaze) or to a third person or an object (joint attention). Shared attention is fundamental to dyadic face-to-face interaction, but how attention is shared, retained, and neutrally represented in a pair-specific manner has not been well studied. Here, we conducted a two-day hyperscanning functional magnetic resonance imaging study in which pairs of participants performed a real-time mutual gaze task followed by a joint attention task on the first day, and mutual gaze tasks several days later. The joint attention task enhanced eye-blink synchronization, which is believed to be a behavioral index of shared attention. When the same participant pairs underwent mutual gaze without joint attention on the second day, enhanced eye-blink synchronization persisted, and this was positively correlated with inter-individual neural synchronization within the right inferior frontal gyrus. Neural synchronization was also positively correlated with enhanced eye-blink synchronization during the previous joint attention task session. Consistent with the Hebbian association hypothesis, the right inferior frontal gyrus had been activated both by initiating and responding to joint attention. These results indicate that shared attention is represented and retained by pair-specific neural synchronization that cannot be reduced to the individual level.


Assuntos
Atenção/fisiologia , Encéfalo/fisiologia , Relações Interpessoais , Feminino , Fixação Ocular , Humanos , Imageamento por Ressonância Magnética , Masculino , Memória , Adulto Jovem
11.
Neurosci Res ; 101: 32-43, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26197267

RESUMO

Affective mentalizing involves the integration of various social signals in order to infer the affective states of others. Previous neuroimaging studies have shown that the medial prefrontal cortex, the precuneus/posterior cingulate cortex, and the temporo-parietal junction constitute the core affective mentalizing network. However, the relative contributions of these regions to affective mentalizing remain unclear. We used functional magnetic resonance imaging to investigate which of these nodes are involved in the integration of two social signals: emotional tears and facial expressions. We assumed that this integration would produce a supra-additive effect, indicated by greater activity than the sum of the effects of the individual social signals. Female subjects rated the sadness of faces with either tears or tear-like circles, and either sad or neutral expressions. We observed the supra-additive effect in the medial prefrontal cortex and precuneus/posterior cingulate cortex but not in the temporo-parietal junction. These results indicate that the medial prefrontal cortex and precuneus/posterior cingulate cortex play an important role in integrating tears and facial expressions during affective mentalizing.


Assuntos
Afeto/fisiologia , Lobo Parietal/fisiologia , Córtex Pré-Frontal/fisiologia , Teoria da Mente/fisiologia , Adolescente , Adulto , Encéfalo/fisiologia , Mapeamento Encefálico , Expressão Facial , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiologia , Lágrimas , Adulto Jovem
12.
Front Hum Neurosci ; 9: 191, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25914637

RESUMO

Using [(11)C]raclopride, a dopamine D2/D3 receptor antagonist, we undertook a positron emission tomography (PET) study to investigate the involvement of the dopaminergic neurotransmitter system when subjects viewed the pictures of partners to whom they were romantically attached. Ten subjects viewed pictures of their romantic partners and, as a control, of friends of the same sex for whom they had neutral feelings during the PET study. We administered [(11)C]raclopride to subjects using a timing for injecting the antagonist which had been determined in previous studies to be optimal for detecting increases in the amount of dopamine released by stimulation. The results demonstrated statistically significant activation of the dopaminergic system in two regions, the medial orbitofrontal cortex (mOFC) and medial prefrontal cortex, the former of which has been strongly implicated in a variety of rewarding experiences, including that of beauty and love. A positive correlation was obtained in mOFC between excitement levels and dopaminergic activation only in the love but not in the control condition.

13.
Soc Neurosci ; 10(1): 16-26, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25188354

RESUMO

Although active listening is an influential behavior, which can affect the social responses of others, the neural correlates underlying its perception have remained unclear. Sensing active listening in social interactions is accompanied by an improvement in the recollected impressions of relevant experiences and is thought to arouse positive feelings. We therefore hypothesized that the recognition of active listening activates the reward system, and that the emotional appraisal of experiences that had been subject to active listening would be improved. To test these hypotheses, we conducted functional magnetic resonance imaging (fMRI) on participants viewing assessments of their own personal experiences made by evaluators with or without active listening attitude. Subjects rated evaluators who showed active listening more positively. Furthermore, they rated episodes more positively when they were evaluated by individuals showing active listening. Neural activation in the ventral striatum was enhanced by perceiving active listening, suggesting that this was processed as rewarding. It also activated the right anterior insula, representing positive emotional reappraisal processes. Furthermore, the mentalizing network was activated when participants were being evaluated, irrespective of active listening behavior. Therefore, perceiving active listening appeared to result in positive emotional appraisal and to invoke mental state attribution to the active listener.


Assuntos
Mapeamento Encefálico , Encéfalo/fisiologia , Comportamento Cooperativo , Emoções , Vias Neurais/fisiologia , Recompensa , Análise de Variância , Percepção Auditiva/fisiologia , Encéfalo/irrigação sanguínea , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Relações Interpessoais , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/irrigação sanguínea , Estimulação Luminosa , Adulto Jovem
14.
Front Hum Neurosci ; 9: 720, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26834613

RESUMO

In a human fMRI study, it has been demonstrated that tasting and ingesting capsaicin activate the ventral part of the middle and posterior short gyri (M/PSG) of the insula which is known as the primary gustatory area, suggesting that capsaicin is recognized as a taste. Tasting and digesting spicy foods containing capsaicin induce various physiological responses such as perspiration from face, salivation, and facilitation of cardiovascular activity, which are thought to be caused through viscero-visceral autonomic reflexes. However, this does not necessarily exclude the possibility of the involvement of higher-order sensory-motor integration between the M/PSG and anterior short gyrus (ASG) known as the autonomic region of the insula. To reveal a possible functional coordination between the M/PSG and ASG, we here addressed whether capsaicin increases neural activity in the ASG as well as the M/PSG using fMRI and a custom-made taste delivery system. Twenty subjects participated in this study, and three tastant solutions: capsaicin, NaCl, and artificial saliva (AS) were used. Group analyses with the regions activated by capsaicin revealed significant activations in the bilateral ASG and M/PSG. The fMRI blood oxygenation level-dependent (BOLD) signals in response to capsaicin stimulation were significantly higher in ASG than in M/PSG regardless of the side. Concomitantly, capsaicin increased the fingertip temperature significantly. Although there was no significant correlation between the fingertip temperatures and BOLD signals in the ASG or M/PSG when the contrast [Capsaicin-AS] or [Capsaicin-NaCl] was computed, a significant correlation was found in the bilateral ASG when the contrast [2 × Capsaicin-NaCl-AS] was computed. In contrast, there was a significant correlation in the hypothalamus regardless of the contrasts. Furthermore, there was a significant correlation between M/PSG and ASG. These results indicate that capsaicin increases neural activity in the ASG as well as the M/PSG, suggesting that the neural coordination between the two cortical areas may be involved in autonomic responses to tasting spicy foods as reflected in fingertip temperature increases.

15.
Neuropsychologia ; 64: 252-62, 2014 11.
Artigo em Inglês | MEDLINE | ID: mdl-25281887

RESUMO

Visual clues as to the physical substance of manufactured objects can be misleading. For example, a plastic ring can appear to be made of gold. However, we can avoid misidentifying an object׳s substance by comparing visual and tactile information. As compared to the spatial properties of an object (e.g., orientation), however, little information regarding physical object properties (material properties) is shared between vision and touch. How can such different kinds of information be compared in the brain? One possibility is that the visuo-tactile comparison of material information is mediated by associations that are previously learned between the two modalities. Previous studies suggest that a cortical network involving the medial temporal lobe and precuneus plays a critical role in the retrieval of information from long-term memory. Here, we used functional magnetic resonance imaging (fMRI) to test whether these brain regions are involved in the visuo-tactile comparison of material properties. The stimuli consisted of surfaces in which an oriented plastic bar was placed on a background texture. Twenty-two healthy participants determined whether the orientations of visually- and tactually-presented bar stimuli were congruent in the orientation conditions, and whether visually- and tactually-presented background textures were congruent in the texture conditions. The texture conditions revealed greater activation of the fusiform gyrus, medial temporal lobe and lateral prefrontal cortex compared with the orientation conditions. In the texture conditions, the precuneus showed greater response to incongruent stimuli than to congruent stimuli. This incongruency effect was greater for the texture conditions than for the orientation conditions. These results suggest that the precuneus is involved in detecting incongruency between tactile and visual texture information in concert with the medial temporal lobe, which is tightly linked with long-term memory.


Assuntos
Lobo Parietal/fisiologia , Percepção do Tato/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Lobo Parietal/diagnóstico por imagem , Estimulação Luminosa , Estimulação Física , Adulto Jovem
16.
J Neurosci ; 34(30): 10096-108, 2014 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-25057211

RESUMO

The visual perception of others' body parts is critical for understanding and imitating their behavior. The visual cortex in humans includes the extrastriate body area (EBA), which is a large portion of the occipitotemporal cortex that is selectively responsive to visually perceived body parts. Previous neuroimaging studies showed that the EBA not only receives sensory inputs regarding others' body information but also receives kinesthetic feedback regarding one's own actions. This finding raised the possibility that the EBA could be formed via nonvisual sensory modalities. However, the effect of visual deprivation on the formation of the EBA has remained largely unknown. Here, we used fMRI to investigate the effect of vision loss on the development of the EBA. Blind and sighted human subjects performed equally well in a haptic-identification task involving three categories of objects (hand shapes, toy cars, and teapots). The superior part (i.e., the middle temporal gyrus and angular gyrus) of the EBA and the supramarginal gyrus showed greater sensitivity to recognized hand shapes than to inanimate objects, regardless of the sensory modality and visual experience. Unlike the superior part of the EBA, the sensitivity of the inferior part (i.e., the inferior temporal sulcus and middle occipital gyrus) depended on visual experience. However, this vision-dependent sensitivity explained minor individual differences in hand-recognition performance. These results indicate that nonvisual modalities drive the development of the cortical network underlying the recognition of hand gestures with a node in the visual cortex.


Assuntos
Gestos , Mãos/fisiologia , Rede Nervosa/fisiologia , Desempenho Psicomotor/fisiologia , Reconhecimento Psicológico/fisiologia , Córtex Visual/fisiologia , Adulto , Cegueira/diagnóstico , Cegueira/fisiopatologia , Encéfalo/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Adulto Jovem
17.
Neurosci Res ; 87: 66-76, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25066523

RESUMO

Detection of the contingency between one's own behavior and consequent social events is important for normal social development, and impaired contingency detection may be a cause of autism spectrum disorder (ASD). To depict the neural underpinnings of this contingency effect, 19 adults with ASD and 22 control participants underwent functional MRI while imitating another's actions and their actions being imitated by the other. As the extrastriate body area (EBA) receives efference copies of one's own movements, we predicted that the EBA would show an atypical response during contingency detection in ASD. We manipulated two factors: the congruency of the executed and observed actions, and the order of action execution and observation. Both groups showed the congruency effect in the bilateral EBA during imitation. When action preceded observation, the left EBA of the control group showed the congruency effect, representing the response to being imitated, indicating contingency detection. The ASD group showed a reduced contingency effect in the left EBA. These results indicate that the function of the EBA in the contingency detection is altered in ASD.


Assuntos
Transtornos Globais do Desenvolvimento Infantil/fisiopatologia , Comportamento Imitativo/fisiologia , Lobo Occipital/fisiopatologia , Autoimagem , Comportamento Social , Adulto , Encéfalo/fisiopatologia , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Desempenho Psicomotor/fisiologia , Adulto Jovem
18.
Soc Cogn Affect Neurosci ; 9(5): 570-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23377900

RESUMO

Individuals can experience embarrassment when exposed to self-feedback images, depending on the extent of the divergence from the internal representation of the standard self. Our previous work implicated the anterior insular cortex (AI) and the anterior cingulate cortex (ACC) in the processing of embarrassment; however, their exact functional contributions have remained uncertain. Here, we explored the effects of being observed by others while viewing self-face images on the extent of embarrassment, and the activation and connectivity patterns in the AI and ACC. We conducted functional magnetic resonance imaging hyperscanning in pairs of healthy participants using an interaction system that allowed an individual to be observed by a partner in real time. Being observed increased the extent of embarrassment reported when viewing self-face images; a corresponding increase in self-related activity in the right AI suggested that this region played a direct role in the subjective experience. Being observed also increased the functional connectivity between the caudal ACC and prefrontal regions, which are involved in processing the reflective self. The ACC might therefore serve as a hub, integrating information about the reflective self that is used in evaluating perceptual self-face images.


Assuntos
Encéfalo/fisiologia , Emoções/fisiologia , Face , Relações Interpessoais , Reconhecimento Visual de Modelos/fisiologia , Autoimagem , Mapeamento Encefálico , Córtex Cerebral/fisiologia , Giro do Cíngulo/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiologia , Adulto Jovem
19.
Front Hum Neurosci ; 8: 1022, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25566037

RESUMO

A community is a set of nodes with dense inter-connections, while there are sparse connections between different communities. A hub is a highly connected node with high centrality. It has been shown that both "communities" and "hubs" exist simultaneously in the brain's functional connectivity network (FCN), as estimated by correlations among low-frequency spontaneous fluctuations in functional magnetic resonance imaging (fMRI) signal changes (0.01-0.10 Hz). This indicates that the brain has a spatial organization that promotes both segregation and integration of information. Here, we demonstrate that frequency-specific network topologies that characterize segregation and integration also exist within this frequency range. In investigating the coherence spectrum among 87 brain regions, we found that two frequency bands, 0.01-0.03 Hz (very low frequency [VLF] band) and 0.07-0.09 Hz (low frequency [LF] band), mainly contributed to functional connectivity. Comparing graph theoretical indices for the VLF and LF bands revealed that the network in the former had a higher capacity for information segregation between identified communities than the latter. Hubs in the VLF band were mainly located within the anterior cingulate cortices, whereas those in the LF band were located in the posterior cingulate cortices and thalamus. Thus, depending on the timescale of brain activity, at least two distinct network topologies contributed to information segregation and integration. This suggests that the brain intrinsically has timescale-dependent functional organizations.

20.
PLoS One ; 8(9): e74958, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24086409

RESUMO

The reputation of others influences partner selection in human cooperative behaviors through verbal reputation representation. Although the way in which humans represent the verbal reputations of others is a pivotal issue for social neuroscience, the neural correlates underlying the representation of verbal reputations of others are unclear. Humans primarily depend on self-evaluation when assessing reputation of self. Likewise, humans might primarily depend on self-evaluation of others when representing their reputation. As interaction promotes the formation of more nuanced, individualized impressions of an interaction partner, humans tend to form self-evaluations of persons with whom they are intimate in their daily life. Thus, we hypothesized that the representation of reputation of others is modulated by intimacy due to one's own evaluation formation of that person. To test this hypothesis, we conducted a functional magnetic resonance imaging experiment with 11 pairs of romantic partners while they viewed an evaluation of a target person (self, partner [intimate other], or stranger [non-intimate other]), made by other evaluators. When compared with strangers, viewing evaluations of self and partner activated overlapping regions in the medial prefrontal cortex. Verbal reputation of self-specific activation was found in the precuneus, which represents self-related processing. The data suggest that midline structures represent reputation of self. In addition, intimacy-modulated activation in the medial prefrontal cortex suggests that the verbal reputation of intimate others is represented similarly to reputation of self. These results suggest that the reputation representation in the medial prefrontal cortex is engaged by verbal reputation of self and intimate others stemming from both own and other evaluators' judgments.


Assuntos
Mapeamento Encefálico , Córtex Pré-Frontal/fisiologia , Autoimagem , Parceiros Sexuais/psicologia , Feminino , Humanos , Julgamento , Imageamento por Ressonância Magnética , Masculino , Desejabilidade Social , Adulto Jovem
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